1. Field of the Invention
The present invention relates to a cooling system for an engine.
2. Description of the Related Art
Japanese unexamined patent publication No. 4-214951 discloses a cooling system for an engine having a plurality of cylinder bores which are arranged along a longitudinal axis of the engine. The system is provided with a first coolant passage continuously extending, on one side of the axis, from the bore arranged in one end of the engine to the bore arranged in another end of the engine along the periphery of the bores; a second coolant passage continuously extending, on the other side of the axis, from the bore arranged in the one end of the engine to the bore arranged in the other end of the engine along the periphery of the bores; a connector for connecting the ends of the first and the second coolant passages located at the one end of the engine; a coolant inlet formed at the end of the first coolant passage located at the other end of the engine; and a coolant outlet formed at the end of the second coolant passage located at the other end of the engine. A coolant flows from the inlet through, in turn, the first passage, the connector, and the second coolant passage, and flows out from the outlet.
An intermediate wall is provided between every two adjacent bores. However, in the system described above, the intermediate walls are not cooled sufficiently. Therefore, it is difficult to reduce undesirable deformation of the bores.